Computer systems often include multiple processors to execute various operations. For example, some computer systems may employ one processor to handle the execution of the main instructions for an operating system (OS) and another processor to handle the execution of I/O operations. A physical communications link, such as a computer network communications link, may be employed to facilitate communication between the various processors. One example of a computer network communications link is an InfiniBand link.
Several drawbacks that impact the overall performance of the computer system are a direct result of the computer network communications link employed to facilitate communication between the various processors in the computer system. For example, some computer network communications links use OS bypass in the main data transfer paths to obtain low latency and high throughput. In addition, some computer network communications links use virtual addresses, as opposed to physical addresses, to describe areas of memory requiring data transfer.
One particular cause of significant performance degradation relates to memory registration and deregistration. For example, computer network communications links require that a virtual address (VA) area be registered with the computer network communications link prior to performing any data transfers with the VA area. In addition, computer network communications links also require that the VA area be deregistered when an I/O operation using the VA area is complete. That is, for each and every I/O operation the VA area to be used for the I/O operation must be registered and deregistered. Because (1) each I/O operation requires a corresponding registration and deregistration of a VA area, (2) different VA areas are used for different I/O operations, (3) registration and deregistration of VA areas are larger-than-normal time-consuming tasks, and (4) many I/O operations are usually performed, the performance degradation of a computer system using a computer network communications link may be prohibitively large.